Abraham Zak was a son of Hartog Zak and Esther de Jong. He married 30 August 1928 in Groningen Roosje Waag, a daughter of Jozef Waag and Mietje van Coevorden.
Abraham had two other sisters Judith and Dina, who also have been killed during the Holocaust.
City Archive of Amsterdam, archive card of Hartog Zak and website www.wiewaswie.nl.